This invention relates to computing resource allocation in a virtual computer system and more particularly to a technology for smoothly changing the allocation of a virtual computer, a network, and a storage apparatus when computing resources are managed on a computing resource tenant-by-computing resource tenant basis (or on a utilization group-by-utilization group basis).
The increase in processor core count and the improvement in virtualization technology have improved the degree of freedom in allocating physical computing resources of a physical computer to a large number of virtual computers as well, thereby making it possible to run a large number of virtual computers with fewer physical computing resources.
It is a common practice for data centers in which many physical computers are kept to rent a plurality of virtual computers to a plurality of clients. For each client (hereinafter referred to as tenant), a data center sets a mode of utilizing a network and a storage apparatus, and sets resources used by the virtual computer in accordance with service level agreement (SLA). An environment where a plurality of tenants uses physical computers within a data center as this is called a multi-tenant environment.
In this type of multi-tenant environment, the data center needs to be run by dynamically allocating a few physical computing resources depending on the loads of the respective tenants in order to improve the profitability of the data center through the enhancement of virtual computer consolidation ratio to physical computing resources.
Known technologies for dynamically changing the allocation of physical computing resources to virtual computers include Distributed Resource Scheduler (DRS) by VMware and Performance and Resource Optimization (PRO) by Microsoft. These technologies are applied to such cases where the load is unbalanced among a plurality of hypervisors (physical servers) constituting a resource group, and a DRS or similar system presents a virtual computer migration plan, or virtual computers are automatically migrated, in a manner that levels the load, to thereby reduce the cost of running by an administrator.
In order to level the load of virtual computers by utilizing the above-mentioned DRS, all physical computers need to share the same LAN switch/SAN switch settings and the same virtual switch settings and storage settings within hypervisors.
However, LAN switch/SAN switch settings include a VLAN or zoning which is set separately for each tenant that uses the data center, and it is therefore difficult to distribute resources among different tenants. There is a known method in which the settings of a physical router or a physical LAN switch are changed to accomplish the migration of physical computing resources between different network segments (for example, Japanese Patent Application Laid-open No. 2010-26699).